A car is travelling on a straight highway. At a certain point its speed is 20 m/s. The driver then follows this schedule:
• increases speed uniformly to 32 m/s in 6 s,
• maintains 32 m/s for the next 10 s,
• applies the brakes so that the car slows down uniformly and comes to rest with a constant retardation of 4 m/s².
Answer the following:
(i) Sketch the complete velocity–time graph for the motion from the instant acceleration begins until the car stops.
(ii) From your graph or otherwise, determine the value of the acceleration during the speeding-up phase and the time taken to come to rest during braking.
(iii) Calculate the distance travelled during each of the three phases and hence find the total distance covered.